DEFICIENT Synonyms: 257 Similar and Opposite Words

deficient

adjective

di-ˈfi-shənt

Definition of deficient

as in incomplete

lacking some necessary part a diet deficient in calcium can lead to weak bones

Synonyms & Similar Words

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Antonyms & Near Antonyms

as in unacceptable

falling short of a standard woefully deficient eyesight kept him out of military service

Synonyms & Similar Words

Antonyms & Near Antonyms

as in lacking

not coming up to an expected measure or meeting a particular need too deficient in common sense to be trusted to stay by himself

Synonyms & Similar Words

Antonyms & Near Antonyms

Example Sentences

Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.

Recent Examples of deficient The bottom line for now is that oysters carry compounds with real biological plausibility for supporting testosterone production, particularly in people who are zinc-deficient. — Samantha Agate, Sacbee.com, 29 July 2026 That narrative, a history-deficient account, often failed to explain how one of the wealthiest colonies in the Caribbean was made poor. — Literary Hub, 27 July 2026 While long-term goals include influencing insurance and investment, their immediate value is assisting understaffed teams manage critical backlogs, such as the 42,404 structurally deficient bridges. — Dara-Abasi Ita, Forbes.com, 23 July 2026 The American Urological Association says that a total testosterone level below 300 ng/dL, when combined with symptoms of low testosterone, should be considered deficient. — Melissa Rudy, FOXNews.com, 20 July 2026 See All Example Sentences for deficient

Recent Examples of Synonyms for deficient

Adjective

Holding an incomplete vote, or one that feeds into any narrative of the winner being illegitimate, would be a tremendous gift to Moscow.

— Nick Paton Walsh, CNN Money, 19 Aug. 2026
On the eve of the new season, Iraola’s squad remains incomplete, particularly in attacking areas.

— Andy Jones, New York Times, 19 Aug. 2026

Definition of incomplete

Adjective

Custard said, for the public, all this adds up to unacceptable risk.

— Yuki Noguchi, NPR, 20 Aug. 2026
But to build a web of accusations based on false premises and the manipulation of reality in order to attack the Biennale and a film invited to compete is a petty and unacceptable act.

— John Bleasdale, Variety, 19 Aug. 2026

Definition of unacceptable

Adjective

Where to Stay Ely hosts a handful of hotels and motels within town limits, but true luxury accommodations are somewhat lacking.

— Stephanie Vermillion, Travel + Leisure, 18 Aug. 2026
Which is to say quality constraints on what Paramount could conceivably dump into theaters are totally lacking.

— Chris Lee, Vulture, 13 Aug. 2026

Definition of lacking

Adjective

The company’s investment in the hedge fund, as well as wrong-way bets in Asian equity markets, drove part of the losses, said the person, who asked not to be identified citing private details.

— Katherine Doherty, Fortune, 15 Aug. 2026
Maybe in this new era, more things will go right than wrong for the Mets.

— Abbey Mastracco, New York Daily News, 15 Aug. 2026

Definition of wrong

Adjective

Deadly fires, often linked to electrical faults or gas cylinder explosions, are common in India where investigators have frequently pointed to safety lapses and inadequate enforcement of fire regulations as contributing to recurring loss of life.

— ABC News, ABC News, 19 Aug. 2026
Having just a dozen countermunitions for interceptions also proved inadequate in the face of large numbers of Ukrainian drones.

— Jeremy Hsu, ArsTechnica, 18 Aug. 2026

Definition of inadequate

Adjective

On the other lies a park in one of the Bronx’s poorest communities, built on the site of the former Yankee Stadium after the old home of the Yankees was torn down in 2009 and 2010.

— Sam Blum, New York Times, 18 Aug. 2026
Iran’s economy was in a dire state before the war too, with poor economic conditions a key driving factor behind the anti-regime demonstrations which kicked off in the Iranian capital city Tehran in 2025.

— Billy Stockwell, CNN Money, 17 Aug. 2026

Definition of poor

Adjective

Toth said that the city had previously addressed allegations made by Saloum in the MDCR investigation, in which the MDCR determined there was insufficient evidence and dismissed Saloum's complaint.

— Karma Sabbah, CBS News, 20 Aug. 2026
And, 94, roughly 20%, were medical grievances related to insufficient medical care and denial of medications.

— Vanessa Romo, NPR, 20 Aug. 2026

Definition of insufficient

Browse Nearby Words

deficiency

deficient

deficiently

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“Deficient.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/deficient. Accessed 21 Aug. 2026.

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Synonyms of deficient

adjective

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